1. Field of the Invention
The present invention relates to a drive for actuating a parking brake. More particularly, the present invention relates to drive for actuating a parking brake operably involving a brake piston being actuatable by an actuating lever with a rotational center.
2. Description of the Related Art
A brake caliper customarily comprises at least one brake disk, at least one brake lining and at least one brake piston. The brake piston presses the brake lining axially and at a right angle against the brake disk. When the driver actuates a known parking brake integrated in the brake caliper a force is applied by a hand brake lever and a Bowden wire fastened to it on the purely mechanical brake caliper. A linear introduction of force is converted into a torque in order to rotate an actuation lever. Finally, the torque must be converted back into a linear introduction of force that presses the brake lining against a brake disk.
In such brake calipers with actuation lever the actuation lever is rotatably fastened in an area of the distal end of the brake piston to a housing around its cup axis. The cup axis is aligned either vertically or transversely, in particular at a right angle, to the axis of the brake piston. A transfer of force takes place in the cup as a function of the cup axis. A vertical arrangement, for example, requires a transfer of force from the lever via an eccentric arranged, e.g., in the cup to the brake piston. The design of the transfer of force from the lever onto the brake piston will not be discussed in detail here.
In addition, hydraulic vehicle breaks have become known in the meantime from DE 197 32 168 C2 (the entire contents of which are incorporated by reference) that realize the above-described function of a parking brake electromechanically. To this end an electromotor is arranged laterally adjacent to a vehicle brake housing. An output shaft of the electromotor runs here with lateral distance parallel to a central axis of a brake piston for the forwarding of force. The output shaft exits from the electromotor on the side facing away from the brake piston. A stepdown gearing acts between the electromotor and the brake piston.
Considering the known vehicle brakes, there is still a problem of providing a brake caliper with an integrated parking brake that is actuated in a conventional manner with a Bowden wire without having to make a basic change to the brake caliper and without considerably more construction space being required. A solution of the problem should be able to be used to the extent possible in all variants of brake calipers.
It is therefore proposed that at least one of the concerns noted is addressed by the proposed electromechanical worm-spindle drive for an actuating parking brake.